CO oxidation on colloidal Au0.80Pd0.20-Fe xOy dumbbell nanocrystals

Chandramohan George, Alessandro Genovese, Alberto Casu, Mirko Prato, Mauro Povia, Liberato Manna*, Tania Montanari

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Scopus citations

Abstract

We report a colloidal synthesis of Au0.80Pd0.20- FexOy dumbbell nanocrystals (NCs) derived from Au 0.75Pd0.25 NCs by metal oxide overgrowth. We compared the catalytic activity of the two types of NCs in the CO oxidation reaction (CO + 1/2O2 → CO2), after they had been dispersed on an alumina nanopowder support. In both cases, the surface active sites were identified by means of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The enhanced catalytic performance of the dumbbell NCs (Au0.80Pd0.20-FexOy) catalyst over that of the initial Au0.75Pd0.25 NCs could be correlated to the presence of the epitaxial connection between the FexO y and the Au0.80Pd0.20 domains (as the main factor). Such connection should result in an electron flow from the metal oxide (FexOy) domain to the noble metal (Au 0.80Pd0.20) domain and appears to influence favorably the nature and composition of the catalytically active surface sites of the dumbbells. Our experiments indicate indeed that, when the metal alloy domain is attached to the metal oxide domain (that is, in the dumbbell), surface Pd species are more active than in the case of the initial Au0.75Pd 0.25 NCs and also Auδ- sites are formed that were not present on the initial Au0.75Pd0.25 NCs.

Original languageEnglish (US)
Pages (from-to)752-757
Number of pages6
JournalNano Letters
Volume13
Issue number2
DOIs
StatePublished - Feb 13 2013

Keywords

  • CO oxidation
  • DRIFT spectroscopy
  • Dumbbell nanocrystals
  • alloy nanocrystals
  • electron-transfer

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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